[krutzger]

I was under the impression that Ubuntu would automatically revert to last good kernel of the new one fails to boot. Was I mistaken?

[michaelt]

There's something close-but-not-quite-the-same: by default the grub menu is hidden with an instant timeout (IIRC) but if a boot fails to complete, on the subsequent boot the menu won't be hidden. Google 'recordfail' if you're interested in the details.

[bproven]

AFAIK worse case you should be able to select the previous kernel in grub2 upon reboot. It just hangs after grub on this (bad) kernel I think...

[ams6110]

Yeah but if you have a couple of hundred machines that aren't booting.... That's pretty worst case.

[jlgaddis]

That is pretty worst case. OTOH, it teaches the lesson about testing updates on a small number of hosts before rolling 'em out globally.

One has to learn that lesson at some point.

[bproven]

yeah - I hear you. :( Still better than being totally hosed...at least there is some option

[myth_drannon]

No, you have to manually restart, boot into grub and select the one that works